1. Field of the Invention
The present invention relates generally to convertible conveyor systems, and more particularly it relates to a conveyor conversion kit for replacing rollers within a roller conveyor system or within a roller supported belt system with an elongated smooth supporting surface for a motor powered endless belt. It also relates to the resulting converted conveyor system, and also to the method of replacing roller conveyors to convert the conveyor system to a motor powered endless belt conveyor.
2. Description of the Prior Art
Roller conveyors are commonly used to provide a conveying surface for a variety of items. Typical roller conveyors include a pair of parallel side walls, or beams, or side rails or rails joined by a series of spaced apart connector bars to form a rigid frame. In between the parallel side walls a plurality of spaced cylindrical rollers are supported. The topmost portions of the rollers define a conveying plane on which to-be-conveyed items are placed and rolled.
To meet changing conveying demands, motor-driven or powered endless belt roller conveyors are often used. Because the rollers in existing conveyors were already in place, it was common practice to use as many of the existing rollers as possible to support a powered endless belt. That is, an endless belt was merely installed on a roller conveyor frame with the rollers acting as the primary supports for the top of the movable endless belt. Typically, such endless belt powered conveyor systems still included the rigid frame formed from a pair of parallel side walls joined by a series of spaced apart connector bars, with the parallel side walls still carrying a plurality of spaced rollers to, as noted above, supports for the top of a movable endless belt.
Typically, an endless belt conveyor is driven linearly between the side walls of the frame by one or more motorized drive roller. The motorized drive roller is located and connected at one or more point along its length of the endless belt conveyor, but is most generally located in about the center of the conveyor system, but may be connected at the head or at the tail, i.e. the beginning or end, of the conveyor frame. In the latter arrangement, the top of the movable endless belt is supported on the top the rollers and drive roller, or when so located, wraps around a head or a tail drive roller. At the same time the bottom of the movable endless belt is generally guided by idler or return rollers.
It is noted, that in practice these idler or return rollers often extend below the support frame structures and are sufficiently out in the open to pose various potential hazards. The exposed idlers or return rollers may pose a significant pinching hazard to workers, or may catch loose materials or a worker's clothing or appendages between themselves and the endless belt. These hazards are more pronounced where the idlers or rollers are in close proximity to a work station area at which location the attention of a worker may be focused on performing a particular task, and therefore distracted from safety considerations. In addition, in an operation in which a conveyor belt moves significant amounts of loose material, such loose materials may adhere to the endless belt and accumulate at critical locations along the endless belt track, thereby subjecting the system to significant additional wear and tear, and premature failure. In addition, it is not unusual for substantial noise to be generated by the rollers and by the endless belt bouncing up and down on the rollers. Furthermore, over time, individual support rollers may become worn or otherwise become damaged and need replacement. Replacing individual support roller is not only expensive, but is time consuming and labor intensive, and also requires that the conveyor system to be inoperative during the replacement of the roller, thereby resulting in down time with the non-productive interruption of movement of conveyed items on the conveyor system.
It is noted that in the known prior parent art, Lapeyre, et al., U.S. Pat. No. 6,269,939 teaches a conversion kit and a method for converting a roller conveyor into a belt conveyor. The converted conveyor is made from a roller conveyor that has a frame with two parallel sides supporting a set of parallel rollers at spaced apart locations. A conversion kit that includes attachment collars that fit around spaced apart selected rollers, while leaving the rollers in place. So called wearstrip material extends outward from the attachment collars and overlies groups of consecutive rollers. The wearstrip material and the collars resting on the rollers form a bed between the sidewalls on which a conveyor belt is supported. However, the resulting converted belt conveyor has the shortcomings that the rollers remaining on the frame tend to catch dirt, dust and debris, and include the possibility of becoming dislodged and falling onto the return portion of the endless belt, thereby posing the possibility of damaging the belt or other parts of the system. It is therefore clearly seen that there is a need for a simple, quick and inexpensive way to convert a roller conveyor into a motor-driven endless belt conveyor that is substantially free of rollers.
In Reatti., U.S. Pat. No. 6,640,966, a support structure for the return section of a belt conveyor, is taught. The support structure is comprised of serpentine slat elements, support members for supporting the serpentine elements, and transverse members to which the support members are coupled. Each serpentine slat element is supported independently of the others by its own independent support members. The support members include on their lower edge, mechanisms for snap-coupling them to the transverse members; the snap-coupling mechanisms being formed in a manner that enables the support members to be coupled by pressing them onto the transverse members. The serpentine slat elements extend between the sidewalls of the return section of a belt conveyor. While this reference does not teach a method for converting a roller conveyor into a belt conveyor, it does teach a return section of a conveyor that is free of rollers. However, the resulting return section of a conveyor has the short comings that it is limited to use at the return section of a conveyor.
Accordingly, there exists a need to provide a conveyor conversion kit for replacing substantially all existing support rollers within a roller conveyor system or within a roller supported belt system with an elongated smooth belt supporting surface for a powered endless belt conveyor. As detailed below, the preferred support roller replacement system of the present invention provides a conveyor conversion kit including modular drop-in style cross supports for such elongated smooth belt supporting surfaces. It also teaches such cross supports with appropriately modified compatible return rollers. It also teaches drop-in drive head and tail motors, and more, as detailed below. It also teaches the resulting converted conveyor system, and also teaches the method of replacing roller conveyors to convert the conveyor system to a motor powered endless belt conveyor.